In most present-day hubs, the unidirectionally-rotating link between the body of the hub and a free wheel body carrying the gears is formed by two tangential ratchets moving in a plane perpendicular to the axis and cooperating with a ratchet wheel, and interposed, with this ratchet wheel, between the aforementioned components.
Cycle users may be only recreational cyclists, but also competitors worried about performance. The latter always seek the strongest and lightest bicycles possible in order to satisfy their passion. The lightness of the components is thus an ongoing concern for manufacturers, but, as regards free wheels, nothing has been improved to date and the various manufacturing components of the free wheel are made of a high-density material such as steel, in order to withstand all of the stresses acting upon them during use of the cycle. Traditionally, therefore, the part attached to the hub body carries the ratchets or teeth, and the free wheel body carries, conversely and respectively, the teeth or ratchets, which are made of steel. Even if, as regards performance levels, this solution proves suitable, the same is not true with respect to weight, which is considered to be too great. It should be noted, moreover, that in present-day systems the part fastened to the hub body and carrying the ratchets is an additional, separate component attached to the hub body, this component being made of steel, as indicated above, while the hub body is made of aluminum.